During certain biopsy procedures, a needle guide may be used through which a portion of an introducer cannula passes. The needle guide serves to minimize non-axial movement or deflection of the introducer during a biopsy to ensure that the introducer is inserted into the correct location of a patient's tissue adjacent a target lesion.
In breast biopsy procedures, for example, an MRI biopsy procedure, needle guides are often used in connection with a compression plate. The compression plate may include a plurality of grid-like openings. Prior to the start of the breast biopsy procedure, the compression plate is pressed against the breast, thereby compressing it, and a needle guide is inserted into one of the grid-like openings where the lesion to be biopsied may be found. The needle guide includes at least one channel extending therethrough. The channel is used through which a portion of an introducer passes. A biopsy needle is then inserted into the introducer.
As the biopsy is being taken, the introducer may unintentionally move in the direction of the z-axis. That is, the introducer cannula may advance further into the breast than intended, or, alternatively, the introducer may partially pull out from the breast as well. One known device for securing the introducer in place is a retaining ring located around an outer diameter of the introducer. The ring includes an outer diameter that is greater than an inner diameter of the channel. Therefore, the introducer is unable to advance further into the breast. However, the ring is unable to restrain the introducer in the opposite direction, away from the breast, and therefore the introducer is still able to partially pull out from the breast.
Accordingly, there exists a need for a device that will secure the introducer such that the introducer is unable to pull out from the breast as the biopsy is being taken.